Evolution and Genetic Engineering: Key Concepts and Challenges

Posted on Nov 17, 2024 in Biology

Gene Therapy

Gene therapy involves inserting genes into cells to treat diseases, including hereditary conditions. In vitro therapy extracts and processes patient cells in a lab, introducing the desired gene before returning them to the patient. In vivo therapy directly introduces a gene-carrying vector into the organism.

Transgenic Plants

Transgenic plants have genes transferred to them for:

  • Herbicide resistance, insect and disease resistance, and increased yield
  • Enhanced photosynthesis
  • Improved product quality
  • Synthesis of commercially valuable products

Transgenic Animals

Applications of transgenic animals include:

  • Studying molecular and embryonic development
  • Manipulating gene expression in vivo
  • Investigating gene function
  • Using mammals as bioreactors for human protein production
  • Increasing milk and meat production

Bioremediation

Bioremediation uses organisms to decontaminate the environment.

Alternatives to Polluting Activities

Mineral extraction and toxic substances can pollute the environment.

Climate and Transgenic Plants

Risks of cultivating transgenic plants include:

  • Potential emergence of food allergies
  • Alteration and loss of biodiversity
  • Gene transmission to wild plants

Social and Political Issues

Human genome knowledge can lead to:

  • Labor and social discrimination
  • Issues with medical insurance and life insurance
  • Violation of personal privacy

Ethical and Moral Concerns

Eugenics is a doctrine based on improving a race through genetic engineering or unnatural selection.

Origin of Biomolecules

Oparin’s hypothesis suggests early biomolecules formed from reactions between gases in Earth’s early atmosphere (H2O, H2, CH4, NH3), powered by solar radiation and electrical discharges. The current hypothesis suggests the early atmosphere was less reactive (N2, water vapor, CO2), with synthesis occurring in volcanic areas emitting methane and ammonia.

Origin of Cells

Some scientists believe early seabed organisms were similar to bacteria, living heterotrophically in the absence of oxygen. As organic matter depleted, they adapted, leading to photosynthetic organisms that produced oxygen, gradually transforming the atmosphere.

Fixism

Fixism posits that species are unchanged since creation, created differently by God. Fossils are remnants of early beings lost to natural disasters.

Lamarck’s Theory

Lamarck’s theory includes:

  1. Inheritance of acquired characteristics: Organisms adapt to changing environments, using some organs more than others. Used organs develop, unused ones atrophy. Acquired traits are passed to offspring.
  2. Inner force: Living things strive for higher complexity, evolving from simple to complex forms.

Darwin’s Theory

  1. Populations produce more offspring than can survive, leading to a struggle for existence.
  2. Intraspecific variability exists, with fitter individuals passing on favorable traits.
  3. Environmental pressure selects the best-adapted individuals, leading to new species over time.

Mutations as a Source of Variability

Mutations are the primary cause of heritable variability within a population.

Adaptation

Adaptation is the ability of organisms to adjust to their environment. This can be:

  • Structural: Affecting organs, like a chameleon’s tongue.
  • Physiological: Affecting body functions, like a bear’s metabolism.
  • Behavioral: Affecting actions, like wolves’ cooperative hunting.

Comparative Anatomy

Homologous organs have the same origin and structure but different functions (e.g., mammal limbs). Analogous organs have different origins but similar functions due to adaptation.

Paleontological Evidence

Fossils provide evidence of evolution, showing extinct ancestors of current species. For example, the horse’s evolutionary line shows changes in size and limb structure.